This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This five year study will compare the primary outcome as measured by the Parkinson's disease functioning, ambulatory gait, cognitive impairment and global functioning in the creatine group versus the placebo group against a background of dopaminergic therapy and best medical practice.